I don't know (I wish I did). Actually are trying to find out for a future project with potentially similar issues. From what I have seen there are a few options.
1) use a less reputable processor but expect lots of failures for processing
2) setup accounts for different sites and use as intermediaries and churn through accounts and stay under the radar long enough to make use of them
3) make enough sales someone will take your business (i've seen a few of these working with VPN companies and contacted them, but they don't care unless you are doing $100k a month)
Don't get me wrong, I am not saying this is exhaustive data, just what I have seen so far.
The UK company / merchant route as mentioned above is interesting if can get merchant account who will turn a blind eye, but the privacy (and the unmentioned tax ) implications don't have me convinced yet
So I spoke more today with some other 3rd party merchant account holders. People can run cc processing for pharma, so, clearly we have a way. The secret is really no secret it turns out as I picked his brain, its pretty much what you are leaning to. Collect data on your site, do not integrate any gateways.
Enter data manually to a virtual terminal. Great customer service to avoid chargebacks, however, its impossible to stop friendly fraud.
Next, set up VCC to be charged daily to your terminal, this will keep chargeback ratio down. To do this manually will be time consuming and drive you crazy. Instead, I am going to create a few hundred VCC and set them on a daily autobill, so if i have 5 sales and all 5 are charged back (100% cb ration), my chargeback ratio after I input the VCC charges, will be 1%.
Obviously the number is based on your sales and business model. Running $1/day trial or something, you need a reason to charge your cards.
Cost will be the cost of the VCC issuer/platform, as well as your rate, say 3.5%+15 cents, so you may be paying a few dollars every day. Scale up/down depending on your needs.
Finally, have backup accounts, have 10 gateways if you can, once you start, keep growing your count until you have a nice reserve.
Finally, I would split charges up between accounts so they all grow slowly and warm up. This way, say you are running 50k/month or more and you get shut down, you
1) dont have a large amount of funds frozen
2) you already have accounts with some volume so there is no question about a rapid spike in sales in one day. You dont want to take an account from 0k to 50K overnight. Now you can spread it all out.
This can be done believe it or not with PayPal stealth accounts. I know of someone (this blew my mind) running 100 PayPal accounts each at 1k/month only to keep them all under the radar. With this method do not run VCC for chargback managament as PayPal will see those charges and ban you ha.
Ideally youll need, phone number, email, name/address, SSN, debit card to withdraw to with same name/address, proof of address would be nice too. If you have all you can probably build the account up to larger than 1k/month. Using VPN etc static IP address im sure too but thats not my department of knowledge.
If accounts get frozen, good thing is, funds will be released after 180 days.